Black holes in anti-de Sitter (AdS) spacetime have attracted a great deal of attention for multiple reasons. It was shown by Hawking and Page [1]} that, unlike black holes in flat spacetime, large black holes in AdS spacetime have positive specific heat and can be in stable equilibrium with thermal radiation at a fixed temperature. Also, according to the AdS/CFT correspondence proposed by Maldacena [2]}, a large static black hole in AdS spacetime corresponds to a thermal state of a system in conformal field theory (CFT).
More specifically, the dynamical time scale for the return to thermal equilibrium in CFT is equal to the decay rate of the perturbation of a large black hole in AdS spacetime.
